Trane 3.5 ton or 4
habi...@my-deja.com
I am replacing my 3.5 ton outside Rheem unit and 4
ton inside unit with a 3.5 ton Trane XL1200 and
XV80 gas furnace. The installer also wants to put
a TXCO54S3HPA coil in. My current system is 11-12
yrs old, but does a good job cooling and heating.
One of the better A/C contractors in town
suggested I might move up to the 4 ton XL1200,
because I am right at the maximum sq ft for the
3.5 ton. Do yall feel this is necessary? He has
me worried about my new system being adequate.
Thanks
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Paul Milligan
>I would appreciate some professional knowledge:
>I am replacing my 3.5 ton outside Rheem unit and 4
>ton inside unit with a 3.5 ton Trane XL1200 and
>XV80 gas furnace. The installer also wants to put
>a TXCO54S3HPA coil in. My current system is 11-12
>yrs old, but does a good job cooling and heating.
>One of the better A/C contractors in town
>suggested I might move up to the 4 ton XL1200,
>because I am right at the maximum sq ft for the
>3.5 ton. Do yall feel this is necessary?
Not based on saure footage, no. Because you simply can not
size an AC unit based on square footage.
Want simple proof ? Build two identical boxes, 1 foot square
each. Stick a thermometer inside each. Insulate the snot out of one,
leave the other plain. Leave them in the sun for a few hours. Check
the temperatures inside. Same square footage, wildly different
temperatures. End of discussion.
RocketD709
idea that the inside and the outside units match each other. In fact, I have
heard that very soon warranties will become voided if this is not done.
I would guess that the larger inside unit was created so that a coil with a
larger surface area could be used. This doesn't mean much to efficiency or
capacity, but it does allow more air to actually touch the cold coil, which
means more humidity can be pulled out of the airstream.
The reason certain coils are used is that the air must maintain a minimum
velocity. Air moving too slow can freeze up, especially if you start getting
dirt on the coils. I would say go with the bigger coils inside because it will
allow the air to move a little bit faster and help prevent the unit from
freezing when dust starts to settle.
As was explained in the other response, house size and air conditioner capacity
don't necessarily have anything to do with each other. However, I would say
that you need about 0.75 cfm per square foot. So for a 2000 sf house, you
would want 1500 cfm. Air conditioners run about 400 cfm per ton, so 1500 cfm
is between 3.5 and 4 tons.
Good luck. I don't always like contractors, but they tend to be right.
Robert Mayfield
Bill"hvac"Spencer
the air. Big is bad and stupid.
<habi...@my-deja.com> wrote in message news:7lh7q0$v9q$1...@nnrp1.deja.com...
> I would appreciate some professional knowledge:
> I am replacing my 3.5 ton outside Rheem unit and 4
> ton inside unit with a 3.5 ton Trane XL1200 and
> XV80 gas furnace. The installer also wants to put
> a TXCO54S3HPA coil in. My current system is 11-12
> yrs old, but does a good job cooling and heating.
> One of the better A/C contractors in town
> suggested I might move up to the 4 ton XL1200,
> because I am right at the maximum sq ft for the
John Mills
>
> I would appreciate some professional knowledge:
> I am replacing my 3.5 ton outside Rheem unit and 4
> ton inside unit with a 3.5 ton Trane XL1200 and
> XV80 gas furnace. The installer also wants to put
> a TXCO54S3HPA coil in. My current system is 11-12
> yrs old, but does a good job cooling and heating.
> One of the better A/C contractors in town
> suggested I might move up to the 4 ton XL1200,
> because I am right at the maximum sq ft for the
> 3.5 ton. Do yall feel this is necessary? He has
> me worried about my new system being adequate.
> Thanks
If a 3.5 ton unit does fine, you & he are nuts to go
bigger. Bigger units cycle more and dehumidify less.
Want it sticky in there? The bull about maximum sq ft
per ton says he doesn't know what he's talking about.
I worry about him being adequate for the job! If he
does go with the bigger unit, make sure he has the
"Comfort-R" feature turned on in the XV80. That will
really increase the moisure sucking of the system.
Nice furnace, I have one too!
--
HVAC Advice, Pictures, Links
http://www.geocities.com/~johnmills
http://www.appelheat.com
AIM: BaldLoonie
ICQ: 18370036
Arthur
loss. This method determines the amount of Btu's required to cool or heat
your home at your location design conditions. That load calculation should
be done accurately & in ACCORDANCE with MANUAL "J". AC contractors should be
able to do this. Now add no more than 15% of the sensible to the total
calculation & that will tell u what ac unit in Btu's is required. This
method takes into account the type of windows & the direction they face, the
type of walls, the number of people, and so on. If u are not familiar or
someone else is not totally familiar with these factors, then DON'T try it.
A competent ac dealer should be familiar. A print out should be provided to
you for your records.
There are other methods but your load should be determined by Manual "J".
Hope this helps,
Arthur
habi...@my-deja.com wrote in message <7lh7q0$v9q$1...@nnrp1.deja.com>...
>I would appreciate some professional knowledge:
>I am replacing my 3.5 ton outside Rheem unit and 4
>ton inside unit with a 3.5 ton Trane XL1200 and
>XV80 gas furnace. The installer also wants to put
>a TXCO54S3HPA coil in. My current system is 11-12
>yrs old, but does a good job cooling and heating.
>One of the better A/C contractors in town
>suggested I might move up to the 4 ton XL1200,
>because I am right at the maximum sq ft for the
>3.5 ton. Do yall feel this is necessary? He has
>me worried about my new system being adequate.
>Thanks
>
>
RReed1999
unit which is 3600 btu to 38 to 3900btus. It was also cheaper to run. I myself
would go a 1/2ton larger.